window.addEventListener('click', function(){
        var form = document.querySelectorAll('.form-control');
        var log = document.querySelector('.login');
        log.addEventListener('click', function () {
            if (form[1].value != 88888888) {
                alert(邮箱或密码错误);
                log.setAttribute('disabled', 'disabled');
            } else {
                log.removeAttribute('disabled');
            }
        })
})